The invention relates to an inflatable airbag for the protection of a person in accordance with the preamble of claim 1. Furthermore, the invention relates to an airbag module as well as vehicle parts, especially a steering wheel, an instrument panel, a rear seat or a rear seat bench, a window frame or a roof liner as well as a piece of garment comprising such airbag. Finally a vehicle occupant restraint system comprising an airbag or an airbag module is indicated within the scope of the invention.
An airbag of the afore-mentioned type is known from WO 2012/044245 A1, for example. The known airbag is part of a protection device for a person's head including the airbag and an outer sheath. The airbag comprises a flexible sheath including fingerlike extensions which delimits a closed gas expansion chamber, and is embedded in an outer bag made of gas-tight material, with the individual fingers of the sheath engaging in receiving pouches of the outer bag. It is provided that the outer bag predetermines the shape of the protection device in the inflated state of the airbag. In other words, the outer bag delimits the expansion of the inner airbag, especially the fingerlike extensions of the inner airbag. This ensures that the protection device takes the desired shape in the inflated state. In the known protection device this shape is especially in the form of a bicycle helmet so that the inflated airbag encloses the person's head of the in a helmet-like manner.
It is a drawback in the known protection device that a relatively high effort has to be made for manufacturing the inner airbag and the outer bag. The functional separation of the inflatable airbag and the shaping outer bag results in a relatively complicated configuration of the protection device and increases the production effort. Finally this results in increased manufacturing costs.
From practice alternative ways of shaping airbags are known. In particular, tethers which tension upon inflation of the airbag and thus delimit the widening or expansion of the airbag may be integrated in the airbag. Tethers of this type may be arranged both inside the airbag and outside the airbag. For example, DE 10 2012 213 284 A1 illustrates an airbag having external tethers which urge the airbag in the inflated state into a three-dimensional shape. These solutions with tethers require additional stitching work and individual parts so that the structure of such airbags is complicated and results in increased production costs.